Method of and means for hydrodynamic mixing

Abstract

A plurality of fluent substances are combined in a distributor (11, 37) and caused to flow in a continuous, pressurized stream through a mixing zone (13, 13', 57) wherein the substances are intimately mixed by turbulent dispersion effected by a series of conically shaped surfaces (24, 27; 62, 64) and alternate restrictions (25, 63) and expansion chambers (28, 65). While various fluent substances may be advantageously mixed, a typical utility is for effecting a thorough air binding of ink particles to attain efficient foaming (29) in the deinking of reconstituted printed paper slurry.

We claim: 
     
       1. Apparatus for attaining an intimate mixture of a plurality of fluent substances in a continuous flow-through passage having an entry end and a discharge end, comprising: means for combining said plurality of fluent substances at said entry end in a continuously flowing stream filling said flow-through passage under substantial hydrodynamic pressure;   means for subjecting said stream in said passage to substantially continuous turbulence and dispersion with mixing effect, and comprising a series of immediately adjacent alternating radially inwardly tapering relatively short conical turbulence surfaces and radially outwardly flaring relatively longer generally conical turbulence surfaces;   means for effecting abrupt transition of the stream from each of said surfaces to the next of said surfaces throughout the entire length of said series;   said surfaces and said abrupt transition means cooperating for attaining continuous and progressively thorough dispersion and mixing of said substances in the continuously flowing stream from said entry end to said discharge end of said passage; and   said discharge end being arranged for discharging the treated stream to receiving means.   
     
     
       2. Apparatus according to claim 1, wherein said combining means comprises means for supplying one of said substances as a fibrous paper and making slurry and means combining another of said substances as a gas with said slurrly. 
     
     
       3. Apparatus according to claim 2, wherein said slurry comprises reconstituted printed paper, and said gas combining means supplies air to said slurry for attaching to ink particles as a result of said dispersion and mixing. 
     
     
       4. Apparatus according to claim 3, wherein said passage discharges the treated stream into an ink separation cell. 
     
     
       5. An apparatus for obtaining an intimate mixture of a plurality of combined fluent substances supplied to said apparatus under substantial hydrodynamic pressure, said apparatus comprising a series of mixing modules defining a continuous, flow-through passage in which mixing occurs; said passage including a series of alternating radially inwardly tapering, relatively short conical surfaces and radially outwardly flaring, relatively longer conical surfaces; and abrupt transition edges between adjacent inwardly and outwardly tapering surfaces such that fluid passing therethrough is subjected continously to the effects of dispersion from said outwardly tapering surfaces or acceleration from said inwardly tapering surfaces throughout the length of said passage. 
     
     
       6. An apparatus as defined in claim 5, and further comprising an outer tube for holding said modules, and said modules being discrete pieces placed in end-to-end relationship in said outer tube.